The popularity and convenience of digital devices as well as the widespread of use of Internet communications have allowed devices to communicate information in a variety of ways. For example, user devices can communicate with each other via wireless communication and using network services providing instant messaging or chat sessions. Some applications can make use of user location sensed by user devices, e.g., by GPS sensors, to enable particular communications. For example, “geofencing” applications can allow communication of information between user devices based on those devices entering defined geographic areas.